"A machine that produces coal. Coal is worth $0 when put into a furnace but is used to power many heavy machines."
The Coal Mine is a Common-tier dropper that produces coal ore worth $0, but is used to power industrial machines (such as the Industrial Ruby Mine and the Industrial Ore Welder etc.). It is often used in that manner, often having the coal travel on conveyor arrays heading to an industrial output.
A premium variant, the Triple Coal Mine and its seasonal variant, the Spooky Coal Mine, produce triple the coal in the same time span, while occupying the same hitbox space, the hitbox being 2x2 units.
Coal's Usefulness Over Time
Coal ore has a history of usage over the span of Miner's Haven.
When the Coal Mine was initially released, it was only compatible with industrial droppers, as the coal had no value in of itself. It was notorious for having the capability to lag servers, due to its unique ore lifetime. Thus, coal wasn't encouraged to be, or was widely used as a result.
On October 10th, 2015, Berezaa released the Industrial Firecrystal Mine, a reborn-tier industrial mine. Since using this mine with a Nature's Grip was useful for low-life players to rebirth fast, more low-life players would buy and use coal mines for this use.
On April 24th, 2016, Berezaa released the Industrial Ore Welder, the first industrial upgrader to be added to Miner's Haven. Due to the Ore Welder's unique properties, it promoted coal usage and Coal became a key player in high-life setups, as it is needed to power the Ore Welder.
The Northern Lights came about on November 13th, 2016. Its massive x500 multiplier requires the power of sparkling coal, provoking players to use devices that grant sparkles to coal to power the Lights. However, getting sparkling coal in the first place is a huge hassle, and therefore Northern Lights wasn't really used that often. The Ultimate Sacrifice, The Second Sacrifice, and the Sakura Garden further cemented Northern Lights' place as a hard-to-use furnace with little-to-no potential in crowded setups (the Sacrifices being Life s-/1000 to be performed, making the player skip a chance on obtaining the Northern Lights; the Sakura Garden has a simple x300 multiplier on pure ores, making it preferable over Northern Lights).
- The Coal Mine's ore is not automatically destroyed upon hitting the floor of a base, making it notorious for ore limit spam at Haven Freebuild servers.
- There is a Premium version of this dropper called the Triple Coal Mine, which drops three coal ore at once but only takes up the same space as a regular Coal Mine.
- Coal ore will despawn after 20 seconds. Even if it is being used as ores in a setup, it will despawn.